Detergent composition



Patented Aug. 15, 1939 PATENT orrics N COMPOSITION William G. Backers, Bolton, N. Y.

No Drawing. Application June 9, 1937,

Serial No. 147,249

Claims.

The present invention relates to detergent compositions in the form of cakes adapted for cleansing and preserving the skin.

While the toilet soaps now in general use have '5 considerable detergent power, they have a number of drawbacks which, despite refinements in their methods of production, have'not been overcome. For example, frequent washing with ordinary soaps afiects the texture of the skin and often results in its becoming roughened or chapped. In recognition of this fact, many specialists recommend that persons with delicate skins reduce washing with soaps to a minimum.

Soaps are composed essentially of salts of naturally. occurring fatty acids and strong bases. Since the-ffatty acids are relatively weak acids, soaps in 'aqueous solution are easily hydrolyzed. Because of this hydrolysis, releasing free alkali, aqueous solutions of soaps are relatively strongly alkaline; in many cases having alkalinities corresponding to pH values of above 10.6. When 1 washing with soap, therefore, the skin is brought into contact with strongly alkaline solutions.

Work by members of the medical profession has.

established that'the human body is covered by.

thin acid-reactinglayers oi epithelial cells that appear to have the function of protecting the 40 A further object of the invention is to provide new detergent compositions which are in the form of firm cakes and which may be easily prepared in an economical manner.

Another object of the invention is to provide a v1 new detergent composition in cake form containing a highly soluble synthetic detergent and dissolving slowly when used for toilet purposes in the ordinary manner.

A still further object of the invention is to pro- 50 vide a simple and economical process for the preparation of the new detergent compositions.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

I have found that a detergent composition in I the form of firm cakes, free of the objectionable properties of ordinary soaps when used for toilet purposes, and possessing therapeutic properties for the skin, may be prepared by combining two materials, either of which when used alone is not ing agents for .,use..primarily in wet treatment 10 processes of textile use similar industries, for example theqalkylated aromatic sulionic acid compounds that contain at least 8 carbon atoms in the alkyl groups and are members of the class I of compounds disclosed in United States Patent 15 2,058,504, the sulfates of long chain aliphatic alcohols known as "Gardinols, and the sulfonated higher fatty acid esters or amides known as Igepons". These detergents are water-soluble compounds I having the; properties of forming 90 aqueous solutions which are substantially neutral or acid in reaction and of being relatively stable to hydrolysis and the action oi hard water, i. e., their calcium salts are substantially soluble in water, From a structural standpoint, the deter- 5 gent ingredients of the synthetic detergents generally are sulfuric acid or phosphoric acid derivatives of alkyl or alkylated' organic compounds, and are generally employed in the form of the water-soluble salts, and particularly the alkali metal (including ammonium) saltsoi. the inorganic acid groups contained therein. The synthetic detergents as commercially prepared usually contain salts such as sodium sulfate in admixture with the detergent ingredient.

Compounds of this nature are diiiicult to prepare in the form of. firm cakes; in most casescakes made of them disintegrate rapidly when placed in water. This defect is not cured by mixing them with inorganic salts such as sodium 40 sulfate, since these salts are highly soluble in water and quickly dissolve out or:v use, permitting the cakes to disintegrate. A further defect apparent in cakes made from detergent compounds of the type under consideration is their property of being susceptible to the abrasive action of the hands when used in the customary way. A much larger quantity of the detergent is rubbed off in the washing operationthan can be effectively dissolved in water and is required for proper cleansso ing.

The other material employed in my new detergent compositions is boric acid. leading to the development of the present inven- 1 tion 1' we indicated that boric acid not only is not 66 injurious to the skin, but has properties that make its use in the treatment of the skin of therapeutic value. Thus, it is mildly acid in reaction, has no tendency to neutralize the normal skin acidity, and stimulates the formation of new epithelial cells necessary for thereplacement of the outer skin. Boric acid alone, however, is not well adapted for use as a skin preservative and restorative, As is well known, boric acid is available in the form of a powder. It has been found that cakes made of this powder, are unsatisfactory because they disintegrate easily when brought into contact with water. Further, the detergent properties of boric acid are weak.

By combining these two materials in suitable proportions, I have found it to be possible to obtain a detergent composition in cake form possessing a combination of the valuable properties of the materials themselves and at the same time being free of their individual disadvantages.

Thus boric acid and synthetic detergentsof the type specified have been found to'be mutual binding agents; cakes made of them being firm and stable against the disintegrating effect of water. Because of the stability of the synthetic detergents to hydrolysis and also because they are salts of stronger acids than boricacid, the compositions have a mildly acid reaction. Due to the relatively low water-solubility of boric acid and the firm manner in which this acid is combined with the synthetic detergents, the boric acid has been found to be effective in reducing the rate at which. the synthetic detergents are used up through solution in water and abrasion. Since boric acid, which may constitute a major proportion oi'the compositions, isrelatively inexpensive, the compositions may be manufactured at less cost than soaps. Also, since boric acid is white in color, the compositions may be manufactured in the form of cakes having a brilliant white color.

The compositions of the present invention may be made in accordance with one method of procedure by mixing together suitable proportions of one or a number of synthetic detergents of the above type and boric acid, and molding this mixture into the form of a cake. The molding may be effected by adding water to the above mixture to convert it to a doughy mass which, apparently because of the heat of solution, becomes warm, and then placing the mass in suitable molds. On cooling, firm, fine-textured cakes are obtained. Alternatively, the cakes may be prepared by heating a suitable mixture of the above materials to soften it and then pressing the softened mixture in molds. Preferably, the boric acid is employed in the form of a powder of a fineness which passes a 60 mesh screen; or finer.

In making up the mixtures to be formed into cakes, widely varying proportions of the synthetic detergent and boric acid may be used. For example, this mixture may contain from about 20 to about per cent by weight of boric acid based on the dry weight of the mixture.

The remainder of the mixture may consist only of the organic synthetic detergent, but inasmuch as the cleansing power of these compounds is often increased by the presence of a water-soluble, substantially neutral or acid, inorganic" salt such as sodium sulfate, sodium chloride, ammonium sulfate, neutral or acid alkali metal phosphates, and the like, preferred compositions contain salts of this nature in addition to boric acid and the synthetic detergent. Commercial preparations of synthetic detergents are sometimes salt-free but ance to hard water.

are usually composed of a mixture of an organic synthetic detergent and a water-soluble nonaikaline inorganic salt. The compositions may also contain other suitable additions such as perfumes or coloring matters, if desired. Compositions of especial value may be prepared in accordance with the present invention by using a mixture consisting of a major proportion of boric acid and a minor proportion of a synthetic detergent which may be admixed with an inorganic salt such as sodium sulfate. The mixture of inorganic salt and detergent may contain relatively purposes while avoiding waste of detergent through abrasion.

As before indicated, the detergents which may" be employed in the preparation of the compositions of the present invention are characterized by their ability to form aqueous solutions" that are substantially neutral or acid in reaction, by their stability to hydrolysis, and by their resist- In general, any detergent which possesses the foregoing properties and which is soluble in water in the presence of free boric acid may be used for the present purpose. The preferred detergents are sulfuric acid or phosphoric acid derivatives of organic compounds, and since these acids are stronger than boric acid, the detergents on being dissolved in water in the presence of boricacid do not react therewith to form appreciable quantities of borates, i. e.. the solutions containfree boric acid. The detergents are employed preferably in the. form of water-soluble salts such as alkali metal (including' ammonium) salts, and particularly sodium salts of the sulfonic acid, sulfuric ester, phosphonic acid, or phosporic ester groups contained in their molecules.

These detergents may be selected from varied classes of compounds falling within the general group of sulfuric acid or phosphoric acid derivatives of alkyl or alkylated organic compounds suitable for use as detergents and emulsifying agents, preferably compounds having an alkyl group of at least 8 carbon atoms. For example,

, the detergents used may be the alkali metal, and particularly the sodium, salts of sulfuric acid or phosphoric acid derivatives of aliphatic alcohols containing at least 8 carbon atoms. As examples of these alcohols there may be mentioned laury] alcohol, oleyl alcohol, stearyl alcohol, cetyl alcohol, etc. The sulfuric acid derivatives of these alcohols may contain sulfonic acid or sulfuricester groups. Products of similar properties which may also be used in the preparation of the new compositions are the compounds obtained by the sulfonation of olefines containing at least 8 carbon atoms.

Another class of compounds which have been found to be particularly valuable for use in the compositions of the present invention are the sulfonated alkylated mononuclear aromatic compounds containing at least 8 carbon atoms in the alkyl groups, disclosed in United States Patent 2,058,504. The detergents employed may also be amides of higher fatty acids, e. g., compounds known as Igepon which are said to be reaction N-methyl derivative acids such as oleic acid. A further class of compou containing at least 8 carbon atoms. These compounds may be made. for example, by reacting an alpha-bromo higher fatty acid with sodium bisulfite and recovering the sodium salt of the reaction product. Among the fatty acids of interest in this connection are stearic acid, palmitic acid, etc. These alpha-sulfonic acid fatty acid compounds may be amidated or esterified in the carboxyl group.

It will be understood that in compounds of the above types, the phosphoric acid derivatives are, in general, equivalents of the sulfuric acid derivatives. These phosphoric acid derivatives may be made by any suitable process, many processes for this purpose being well known.

The following examples are illustrative of compositions included within the scope of the invention and of methods of making them. The parts are by weight.

Example 1.--A mixture of 65 parts of boric acid powder of a fineness which passes a mesh screen and 15 parts of a commercial detergent known as Gardinol and consisting of about equal parts of the sodium salt of sulfated technical lauryl alcohol and sodium sulfate is ground in a ball mill until it is converted into a powder consisting of auniform mixture of the ingredients which passes a 60 mesh screen. The ground mixture is then screened to remove particles larger than 60 mesh. 20 parts of cold water are added to the screened mixture while stirring, and a warm, doughy mass is formed. This mass is placed insuitable forms or molds and on cooling, firm, solid cakes are obtained. These cakes when brought into contact with water do not become soft and when removed from water quickly dry out.

Example 2.-'75 parts of boric acid powder are ground in a ball mill with 25 parts of a product consisting of about equal parts by weight of sodium sulfate and a mixture of the sodium salts of alkylated mononuclear aromatic sulfonic acids in which the alkyl groups contain at least 8 carbon atoms prepared as described in Example 1 of United States Patent 2,058,504 from commercial cetyl alcohol and phenol followed by sulfonati on and neutralization. The resulting fine-.

, ly-ground mixture of boric acid and detergent,

after screening through a 60 mesh screen, is placed in suitable molds. The molds are warmed to about 60 to 70 C. to soften the mixture which is subjected to a pressure of about 6000 pounds per square inch. Firm, hard cakes are obtained.

By proceeding in a similar manner to that described in the above examples, but employing in place of the detergents used therein, any one or a mixture of the detergents of the type before disclosed, detergent compositions in cake form having similar properties may be obtained. While the detergents used preferably contain admixed therewith a proportion of sodium sulfate, ammonium sulfate, or similar salt, detergents which are free of such salts may be used if desired.

H Further, although the preferred compositionsaie those whichcontaina major proportion. of boric acid, compositions containing as little as 20 per cent by weight are included within the scope of ds which maybe, employed are the water-soluble salts of alphasulfonic acid derivatives of saturated fatty acids:

the invention. As above indicated, of especial importance are the compositions which contain from about 50 to about 80 per cent of boric acid based on the dry weight of the compositions. The remainder of these preferred compositions may be made up of one of the foregoing synthetic detergents, i. e., these compositions may contain from about 50 to about 20 per cent of one of the above synthetic detergents. Ordinarily, however, the remainder of these compositions will be made up of an ordinary commercial preparation of a synthetic detergent, i. e., a preparation consisting of a combination of an organic synthetic detergent and a non-alkaline water-soluble inorganic salt such as sodium sulfate and ammonium sulfate. Where in the claims a watersoluble synthetic detergent is referred to it will be understood that such commercial preparations, as well as salt-free preparations, are intended. Further, it will be understood that the compositions may, if desired, contain a small quantity of suitable additions such as perfumes, etc.

In the above examples, sodium salts of the detergents are employed. It will be understood that other salts such as organic amine salts and particularly other alkali metal salts (including ammonium salts) may also be used if desired.

From the foregoing description it will be apparent that the present invention provides detergent compositions in cake form containing boric acid and a. synthetic detergent of the'class specifled which compositions are excellently adapted for use for toilet purposes. Since the synthetic detergents aresalts of stronger acids than boric acid, the basis atoms or groups attached to the inorganic'acid groups are not released so as to be capable of reacting with boric acid to form borates. g,

The present invention, therefore, pro des a detergent composition in cake form adapted for use for toilet purposes which, as distinguished from ordinary soaps, has a mildly acid reaction and does not disturb the acid balance of the skin; a balance which has been provided to protect the bodyagainst bacteria. While the detergent compositions have an acid reaction, this reaction is so mild that when their lather accidentally gets into the eye it does not sting as is the case with the lather of ordinary alkaline reacting toilet soaps. The new compositions, therefore, are of especial value for use as baby soaps. The detergent compositions have been found to have excellent properties when used as shampoos since they leave the hair in a natural condition. The presence of boric acid in the detergent compositions give their lather a healing effect on rough or cut portions of the skin and stimulates the formation of new epithelia to replace the worn-off outer skin. Further, as already indicated the'compositions of the present invention may be used in hard water without forming insoluble calcium and magnesium soaps. Since the foregoing description has been given for the purposes of illustration, it will be understood that the invention is not limited thereto. The scope of the invention is indicated in the appended claims.

I claim:

1. A detergent composition in cake form adapted for toilet purposeswhich is mildly acid in reaction and possesses good lathering and cleansing properties comprising a mixture composed of boric acid and a water-soluble synthetic detergent comprising a water-soluble salt of a derivative than, said composition being composed of about 20 to about 80 per cent of borlc acidbased on the dry weight of the composition and about 80 to about 20 per cent 01 said water-soluble synthetic detergent.

2. A detergent composition in cake form adapted for toilet purposes which is mildly acid in reaction and possesses good lathering and cleansing properties comprising a mixture composed of boric acid and a water-soluble synthetic detergent consisting of a combination of a water-soluble non-alkaline inorganic salt and a water-soluble salt of a derivative selected from the group consistingof the sulfuric acid and phosphoric acid derivatives of an organic compound containing an alkyl radical having at least 8 carbon atoms, the water-soluble non-alkaline inorganic salt constituting up to about 60 per cent by weight of said combination, said water-soluble-salt of a derivative selected from the group consisting of the sulturic acid and phosphoric acid derivatives of an organic compound containing an alkyl radical having at least 8 carbon atoms being characterized by its stability to hydrolysis and its resistance to hard water, the boric acid acting as a binding agent in the composition, said composition being composed of about 20 to about 80 per cent of boric acid based on the dry weight of the p the boric acid acting as composition and about 80 to about 20 per cent of said water-soluble'synthetic detergent.

3. A detergent composition in cake form adapted for toilet purposes which is mildly acid in reaction and possesses good iathering and cleansing properties comprising a mixture composed of boric acid and a water-soluble synthetic detergent comprising an alkali metal salt of a sulfuric acid being characterized derivative of an organic compound containing an-alkyl radical having at least 8 carbon atoms, said alkali metal salt being characterized by its stability to hydrolysis and its resistance to hard water, the boric acid acting as a binding agent in the composition, said composition being composed of about 20 to about 80 per cent 01' boric acid based on the dry weight of the composition and about 80 to about 20 per cent of said watersoluble synthetic detergent.

4. A detergent composition in cake form adapted for toilet purposes which is mildly acid in reaction and possesses good lathering and cleansing properties comprising a mixture composed of boric acid and a water-soluble synthetic detergent comprising an alkali metal salt of an alkyl sulfuric acid ester in which the alkyl group contains at least 8 carbon atoms, said alkali'metal salt and its resistance to hard water, the boric acid acting w a binding agent in the composition, said composition beingcomposed of about 50 to about 80 per cent of boric acid based on the dry weight of the composition and about 50 to about 20 per cent of said water-soluble synthetic detergent.

5. A detergent composition in cake form adapted for toilet purposes which is mildly acid in reaction and possesses good lathering and cleansing properties comprising boric acid and a watersoluble synthetic detergent consisting of a combination o: sodium sulfate and the sodium salt of the acid sulfuric acid ester oi technical lauryl alcohol, the sodium sulfate constituting up to about 60 percent by weight of said combination. a binding agent in the composition. said composition being composed of about 50 to about 80 per cent of boric acid based on the dry weight of the composition and about 50 to about 20 per cent of said water-soluble synthetic detergent.

' WILLIAM G. BECKERS.

by its stability to hydrolysis 

